A classic case of a poor argument starts with an unreferenced text. It is also one that falls to selective replying to sources provided.
The next paragraph of what text??? I cited several and referenced them all.
The conclusion of 'he doesn't put anything in addition to scripture' is based on the translator's comment, at best, not Ireneaus himself.
However the translator simply refers to that scripture that says to standfast to teaching whether by scripture or tradition.
It also assumes the as yet unproven point; that the Orthodox church has traditions contrary to scripture.
So if we simply take a translators comments and then say that's what Irenaeus says and apply it to a theory that's not been proved here (regarding the Orthodox church and its traditions) one might begin to have a case.
But it's still missing the point of tying tradition and scripture which is the Orthodox doctrine.
If one is to believe the interjection here then it is saying that they of the same value, NOT that one should rely on scripture alone.
The last thing I cited, the next chapter has this telling title:
Chapter III.—A refutation of the heretics, from the fact that, in the various Churches, a perpetual succession of bishops was kept up.
Against Heresies Book III
http://www.ccel.org/ccel/schaff/anf01.ix.iv.iv.html
Irenaeus goes on to say
1. It is within the power of all, therefore, in every Church, who may wish to see the truth, to contemplate clearly the tradition of the apostles manifested throughout the whole world; and we are in a position to reckon up those who were by the apostles instituted bishops in the Churches
Now here emerges the problem of those selectively quoting him as an authority for they often deny apostolic succession nor do they follow bishops.
I have asked some in the past which bishop do they follow. The answer, if given is 'Christ'.
However Irenaeus is talking of a succession of bishops to another bishop. He lists bishops in one See as an example and states
"And this is most abundant proof that there is one and the same vivifying faith, which has been preserved in the Church from the apostles until now, and handed down in truth."
(Ibid.)
NOT that they relied solely on scripture!
In fact apostolic succession is denied by many Protestants as being biblical
Irenaeus refers to a non-biblical authority:
There is also a very powerful Epistle of Polycarp written to the Philippians, from which those who choose to do so, and are anxious about their salvation, can learn the character of his faith, and the preaching of the truth. Then, again, the Church in Ephesus, founded by Paul, and having John remaining among them permanently until the times of Trajan, is a true witness of the tradition of the apostles.
(Ibid.)
And here we see what Irenaeus means by tying scripture with tradition. For him 'scripture' is not just the Bible but the writings of other Fathers!